Method of gravure reproduction



Nov. 24, 1959 J. G. CONSAUL ET AL MEII'I-IOD 0F GRAVURE REPRODUCTIONFiled July 26, 1955 STEPI MAKE A CONTINUOUS-TONE NEGATIVE FROM COPY TOBE REPRODUCED MAKE A CONTINUOUS-TONE POSITIVE STEP2 FROM THECONTINUOUS-TONE NEGATNE OF STEP I STEP 3 MAKE PHOTOGRAPHICALLY A LINESCREEN NEGATIVE DIRECTLY ON A LIGHT SENSITIVE RESIST FROM THECONTINUOUS- TONE POSITIVE OF STEP 2 STEPS TRANSFER RESIST TO COPPERCYLINDER OR PLATE, DEVELOP AND ETCH IN THE USUAL WAY INVENTORS. JOHN G.CONSAUL EDWIN VEL-T EN BY A ATTORNEY United States Patent M rmrnon 0FGRAVURE REPRODUCTION John G. Consaul, Bayonne, and Edwin Velten,Gladstone, N.J., assignors to Art Color Printing Company, New York, N.\.and Dunellen, N.J., a corporation of New York Application July 26, 1955,Serial No. 524,459

3 Claims. (Cl. 96-38) This invention relates to a method of gravurereproduction, and more particularly to certain improvements in themethod disclosed in our copending application, Serial No. 524,458 filedon July 26, 1955, and entitled Method of Gravure Reproduction.

The primary object of the present invention is to simplify the method ofsaid copending application by omitting certain steps thereof. Theinstant method eliminates the necessity of making screened negatives andpositives as in the former case. According to the present method a linescreen negative and an unlined or unscreened negative are formedsuccessively on a light sensitive resist directly from a continuous-tonepositive that has a photographic image thereon of the copy or subject tobe reproduced.

Another object is to provide an improved method that avoids theform'mounting heretofore required to register two exposures on acarbon-tissue in the practice of the prior methods. Form mounting is atime consuming operation that requires a high degree of skill. Thepresent method, while preserving the advantages of our former methodwith respect to increased tonal range, by eliminating form mountingeffects a marked economy in time and labor. It also obviates printing ona carbontissue.

Other objects and advantages will appear from following description ofthe invention, reference being had to the accompanying drawing whichillustrates a flow sheet on which the steps of the method aredesignated.

By the term line screen negative used in the specification and claims isthe negative that results from simultaneous exposure through both ahalf-tone screen, and an auxiliary screening device. The term auxiliaryscreening device as used hereinafter and in the claims means a screeningdevice of the kind described in our Patent No. 2,703,281 of March 1,1955.

The first step in the practice of the present method is to make acontinuous-tone negative of the copy or subject to be reproduced. Acontinuous-tone positive is then made from this negative in the usualway. Both the continuous-tone negative and the continuous-tone positivemay be retouched as required. In the case of multicolor work the usualcolor separation negatives and positives are made. No invention ornovelty is claimed as to these steps in themselves.

The following two steps, designated as steps 3 and 4 on the drawing,distinguish our method from all prior art gravure reproduction methodsof which we are aware. According to step 3 a line screen negative ismade photographically from the continuous-tone positive of step 2directly on a resist of a light sensitive silver emulsion film or thelike. In making the line screen nega- 2,914,406 Patented Nov. 24, 1959tive, the resist is exposed through both a half-tone screen and anauxiliary screening device that comprises a disk or stop having aplurality of circular openings arranged in two straight lines that crosseach other at a right angle, which openings are centered with respect tothe squares or reticulations of the half-tone screen. This results informing on the resist a dotted image of the copy.

In step 4 of the method an unlined or unscreened negative is made on thesame resist from the continuous-tone positive. In carrying out thisstep, the half-tone screen and the auxiliary screening device areremoved from the camera and the resist is re-exposed to thecontinuoustone positive to form an image thereof directly upon the linescreen image previously formed on said resist.

As the final step of the method the resist is transferred to the surfaceof the printing cylinder or plate, and the surface is then developed andetched in the usual way.

What we claim is:

1. The method of gravure reproduction which comprises making acontinuous-tone negative from the copy to be reproduced, making acontinuous-tone, unscreened positive from said negative, making a linescreen negative of said continuous-tone positive on a light sensitiveresist by exposing the resist photographically to said positivesimultaneously through a half-tone screen and an auxiliary screeningdevice comprising an opaque member having a plurality of spaced circularopenings therethrough arranged in two straight lines that cross eachother at a right angle and are centered with respect to squares of thehalf-tone screen, re-exposing the resist to said continuous-tonepositive with said screens removed to make an unlined image thereofdirectly upon the line screen image formed on said resist, andtransferring the resist to the printing surface, developing and etchingsaid surface.

2. In a method of gravure reproduction the steps which consist in makinga continuous-tone, unscreened positive of the copy to be reproduced,making a line screen negative directly on a light sensitive resist fromsaid continuous-tone positive by exposing the resist photographically tosaid positive simultaneously through a half-tone screen and an auxiliaryscreening device comprising an opaque member having a plurality ofspaced circular openings therethrough arranged in two straight linesthat cross each other at a right angle and are centered with respect tosquares of the half-tone screen, and re-exposing the resist to saidcontinuous-tone positive with said screens removed to make an unlinedimage directly upon the line screen image formed on said resist.

3. The method of making an intaglio gravure printing plate or cylinderwhich comprises making a continuoustone positive of the copy to bereproduced, making a line screen negative of said continuous-tonepositive on a light sensitive resist by exposing the resistphotographically to said positive simultaneously through a half-tonescreen and an auxiliary screening device comprising an opaque memberhaving a plurality of spaced circular openings therethrough arranged intwo straight lines that cross each other at a right angle and arecentered with respect to squares of the half-tone screen, re-exposingthe resist to said continuous-tone positive with said screens removed tomake an unlined image thereof directly upon the line screen imageformedon said resist, and transferring the resist to the printingsurface of said plate or cylinder, developing and etching said surface.

References Cited in the file of this patent UNITED STATES PATENTS2,040,247 Dultgen May 12, 1936 2,060,640 Shaw Nov. 10, 1936 2,096,794Dultgen Oct. 26, 1937 4 2,182,559 Henderson Dec. 5, 1939 2,703,281Consaul et a1 Mar. 1, 1955 2,731,346 Gresham Jan. 17, 1956 FOREIGNPATENTS 128,926 Australia Aug. 27, 1948 OTHER REFERENCES Cartwright etal.: Rotogravure, McKay Pub. Co. Inc., Lyndon, Kentucky, 1956.

1. THE METHOD OF GRAVURE REPRODUCTION WHICH COMPRISES MAKING ACONTINOUS-TONE NEGATIVE FROM THE COPY TO BE REPRODUCED, MAKING ACONTINUOUS-TONE, UNSCREENED POSITIVE FROM SAID NEGATIVE, MAKING A LINESCREEN NEGATIVE OF SAID CONTINUOUS-TONE POSITIVE ON A LIGHT SENSITIVERESIST BY EXPOSING THE RESIST PHOTOGRAPHICALLY TO SAID POSITIVESIMULTANEOUSLY THROUGH A HALF-TONE SCREEN AND AN AUXILIARY SCREENINGDEVICE COMPRISING AN OPAQUE MEMBER HAVING A PLURALITY OF SPACED CIRCULAROPENING THERETHROUGH ARRANGED IN TWO STRAIGHT LINES THAT CROSS EACHOTHER AT A RIGHT ANGLE AND ARE CENTERED WITH RESPECT TO SQUARES OF THEHALF-TONE SCREEN, RE-EXPOSING THE RESIST TO SAID CONTINUOUS-TONEPOSITIVE WITH SAID SCREENS REMOVED TO MAKE AN UNLINED IMAGE THEREOFDIRECTLY UPON THE LINE SCREEN IMAGE FORMED ON SAID RESIST, ANDTRANSFERRING THE RESIST TO THE PRINTING SURFACE, DEVELOPING AND ETCHINGSAID SURFACE.